https://openjdk.java.net/ 
public interface sun.swing.UIClientPropertyKey
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: sun.swing.UIClientPropertyKey
  super_class: java.lang.Object
{
}
SourceFile: "UIClientPropertyKey.java"